Multiple lever tool



7 Jan. 22, 1963 Filed Jan. 3, 1962 T. M. PORTER MULTIPLE LEVER TOOL 2Sheets-Sheet 1 "W ll Inve222ba Taiomms M.Po3 ei Jan. 22, 1963 Filed Jan.3, 1962 T. M. PORTER MULTIPLE LEVER TOOL 2 Sheets-Sheet 2 ited ' stateThis invention relates to tools of the multiple or compound lever typein which jaws which operate on the work are pressed against it throughthe operation of a toggle moving towards the straightened position, andthe object is to provide an improved construction which permits therelative positions of the pivotal centers to be adjusted as necessary tocontrol the action.

Multiple lever tools of the type disclosed in the patents to Lindsay146,829 and 147,850 in which the jaws are actuated by a toggle are wellknown and the tool herein illustrated and described is of that generaltype. Heretofore various constructions have been provided for adjustingthe relative positions of the pivotal centers of the toggle, andrecently the patent to Klein, 2,910,900, has disclosed a constructionwherein a massive portion of one lever is cleft to provide integralpivot-supporting parts for receiving the centers of a toggle link whichparts are substantially inflexible under minor bending pressure, yet maybe deformed without danger of fracture in order to adjust the spacing ofthe pivots, the deformation being effected by means of a jackscrewcarried by one part and bearing on the other and serving to take thethrust of heavier working loads. The present invention provides meansfor relatively positioning the projecting pivot-supporting parts in useand providing for adjustment of their relative positions, which meansleaves the parts intact, avoids the presence of a laterally projectingscrew which may be fouled in use, and generally provides a neater andmore compact structure, simple to manufacture and of superior strength.

The invention will be well understood by reference to the followingdescription of the embodiment thereof shown by way of example in theaccompanying drawings, where- PEG. 1 is a front view of an adjustable,hand-driven, toggle-operated tool of the kind commonly called a boltclipper constructed in accordance with the invention, the parts being inclosed position;

FIG. 2 is a front view of the forward end portion of the left-handoperating lever of the tool on a larger scale;

FIG. 3 is a central vertical section through the expanding andsupporting block of FIG. 2 on an enlarged scale, with parts broken away;

FIG. 4 is a section on lines 44 of FIG. 3;

FIGS. 5 and 6 are views similar to FIG. 2 but showing differentstructural embodiments; and

FIG. 7 is a section on line 7-7 of FIG. 1.

In the following description the words right and left have been usedwith reference to the drawings and the words forward and rearward areused from the point of view of a user grasping the tool at the lower endviewing FIG. 1 and holding it extended away from his body, forward beingtoward the jaw-carrying end at the upper portion of FIG. 1 and rearwardin the direction of the handle extremities at the bottom of FIG. 1. Thewords are of course relative for convenience of description and have noinherent significance.

Referring now to the drawings, the tool shown comprises a pair of headlevers l3 and 14 which are pivoted together and herein, since the leversdo not cross, they are pivoted at intermediate points of their length onplates 15. The forward portions are jaws 20* and 21,

I, 3,674,354 Patented Jan. 22, 1963 which as shown have opposed edges ofthe nipper type which moving toward one another first indent the workand, as their motion together proceeds, sever it and the rearwardlyextending portions 22 and 23 are tails which when forced apart cause thejaws to move together and operate on the Work. The actuating levers l1and 12 which move the jaw tails are, mechanically speaking, bent leversherein illustrated as having a compound construction not necessary todescribe and not essential to the invention, and these levers have attheir forward extremities knuckle portions 33 and 34 (see FIG. 7)receiving a central pivot it? joining them together and, respectively atpoints closely adjacent to this pivotal point 40, knuckles 32 and 35(see FIG. 7) which are joined to knuckles 22 and 23 on the tails of thehead levers by pivot pins to provide relatively short arms organized asa toggle of which the centers are 40, 41 and 42, although in the exampleillustrated the short arm between the centers 40 and 42 does notphysically extend in a straight line between them. The actuating leversare extended beyond the centers 41 and 42 rearwardly, and herein formlong actuating handles 11 and 12.

The tool shown is adapted to be operated by the hands of the operatorgrasping the rearward ends of the levers, moving the same togetherwithout the intervention of mechanical or power-increasing mechanisms ormotordriven mechanism, the application of which to such actuating armsis however sufiicientl'y obvious. t is not necessary that both leversmove.

Referring to FIG. 1 it will be seen that if the levers 11 and 12 weremoved outwardly to the right and left respectively, the center 46 of thetoggle would move downwardly drawing together the centers 41 and 42 andopening the jaws 20' and 21 of the tool. In the opposite action thetoggle is straightened, presses the centers 41 and 42 apart with greatforce and exerts correspondingly great pressure on the work. Inaccordance with the invention the relative position of the three centers40, 41 and 42 of the toggle is subject to adjustment and herein 1 haveshown such adjustment at the left-hand side viewing FIG. 1. For thispurpose the forward end portion of the bent lever at the left includingthe forward end of handle 12 and the knuckles 34 and 35, consists of amassive body of suitable metal, preferably forged steel, which isductile in the sense that it may be deformed by the means to bedescribed without danger of fracture, but having such yield strengththat in the cross sections involved the parts will be substantiallyinflexible under 50 minor bending pressures substantially lower thanthose exerted by means of the toggle mechanism. Theknuckles 34 and 35which receive the pivots 40 and 42 are formed in this block of metalwhich as best seen in FIG. 2 is cleft rearwardly in a plane extendingbetween those knuckles to provide integrally based pivot-supportingparts 44 and 4,5 for supporting the pivots at centers 40 and 42respectively, the knuckles 34 and 35 being at the outer ends thereof.These parts are substantially inflexible for instance in the movementclockwise about the center 4.0 where the load is merely that involved inopening the aws.

Apart from a few details the preceding three paragraphs would be equallyapplicable to the structure disclosed in the Klein Patent 2,910,900already referred to and intentionally substantially duplicate a portionof the specification of that patent.

Referring now to the left-hand side of FIG. 2, the forward portions ofthe internally facing side of the pivotsupporting parts 44 and 45 atopposite sides of the cleft are provided with rearwardly and inwardlyinclined surfaces 46, with which cooperate the sides of a rearwardlytapered block 48 of generally rectangular cross section,

and it will be apparent that if the block 48 is forced rearwardly,downwardly in the figure, between the two parts 44 and 45, it will wedgethem apart, separating the knuckles 34 and 35 and centers 49 and d2.'Herein the block is traversed (see FIG. 4) by a bolt 59 on which itswivels, being retained by the head 54, the thread of the bolt enteringa thread in the body at the base of the cleft. A recess 52 in the headof the bolt has flat sides to receive a wrench of the type commonly usedfor setting up hollow-headed setscrews. Screwing in the bolt draws theblock downwardly between the converging surfaces 45 and the block whenat rest supports the two parts 43 and 45 from inward movement toward oneanother.

The word wedge is put in quotation marks in the preceding paragraph. Thesurfaces 46 may correspond to the sides of a triangular prism, but itwill be apparent that if the pivot supporting parts 44 and 55 are forcedoutwardly they tend to swing about their inner ends and the anglebetween the surfaces 46 will change. If the block 43 were similarly a.trangular prism it would engage only at its inner edge as the two pivotsupporting elements move apart and would act at a point relatively farremoved from the centers 4%) and 42. Therefore, preferably the block isshaped as in F168. 3 and 4, the sides being curved. The side elevationmight be characterized as a truncated ogive. if the block 43 movesrearwardly the surfaces 46 move along these curved surfaces of theblock, the line of contact moving rearwardly but being maintainedthroughout the transverse width of the block. These sides of the blockmay be relieved centrally as best seen at 55 in FIG. 4, to provide aprojecting rib at each side so that the bearing of the block on each ofsurfaces -36 is along two narrow zones at either side of the centralplane. In effect there are then two members acting symmetrically to thecentral plane for supporting and for flexing the pivot-supporting parts,which members are supported from a central core to which the force tomove them is applied by means of the screw.

In FIG. the block 48, instead of being swiveled on the unthreaded end ofa screw bolt, is threaded onto one end of a screw Eda, the other end ofwhich screws into a threaded opening at the base of the cleft as in theconstruction of PEG. 2. An angular portion 52a is provided for theapplication of a turning tool. Since the distance which the block 48moves is short, but the force which it must exert to. flex parts 4 and45 is great, this compound screw preferably has threads of the samehand, but with dilferent numbers of turns per inch, so that turning ofcompound screw Sba in a direction to unscrew one end, tends to screw inthe other. That is, Etta is then a diiferential screw. The movement ofthe block is slow, and a high mechanical advantage is provided to permitapplication of the deforming force to the parts 44 and 45.

In the modification shown in FIG. 6 the surfaces 4615 at the inner faceof pivot-supporting parts 44 and 45 incline rearwardly and outwardlyinstead of rearwardly and inwardly as in the case of the similarlylocated surfaces in FIGS. 2 and 5, andthe block 48b is invertedrelatively to block 4-8 in those figures, and it acts to force apartcenters 4b and 42 when it is moved forwardly. For this purpose it may bemounted on a screw 59b the lower end of which is rotatably stepped in asocket at the base of the cleft, and the screw 59b is provided with anenlarged portion 52b to which a turning tool may be applied. The blockis held from turning with the screw by means of small plates 56 attachedthereto and overlying the sides of the parts 44 and The construction isof particular utility in small tools wherein the distance between thecenters 4% and 42 is relatively short. Where space is ample the othermodifications may be preferred as the body element would be easier tomachine.

I am aware that the invention may be embodied in other specific formswithout departing from the spirit or essential attributes thereof, and Itherefore desire the present embodiment to be considered in all respectsas iilustrative and not restrictive, as is in fact clear in severalmatters from the description itself. Reference is to be had to theappended claims to indicate those principles of the inventionexemplified by the particular embodiment described and which I desire tosecure by Letters Patent.

1 claim:

1. In a tool of the multiple lever type comprising:

(a) a pair of interpivoted head levers having workdeforming jaws at oneside of the pivot and tails on the opposite, and means for moving thetails comprising two actuating levers pivoted together at their forwardends and, adjacent to their common pivot, being pivoted respectively tosaid tails to provide short arms extending between the tails as atoggle, the actuating levers extending rearwardly from the tails toprovide actuating arms to which force may be applied to operate thetoggle,

(b) and in which tool the forward end portion of at least one of theactuating levers is a massive integral body of ductile metai in whichbody the pivots are organized, the body being cleft rearwardly in aplane extending between said pivots to provide integrally basedprojecting pivot-supporting parts essentially inflexible as againstsmall strains,

(c) the combination with said cleft body of a block interposed betweenthe pivot-supporting parts, sides of the block and said parts beingshaped to provide outward lateral pressure on the latter to flex thesaid parts as the block is moved in one direction lengthwise betweenthem and a device comprising a rotatable screw on the space between saidparts and extending between said block and the bottom of the cleft foradjnstably positioning the block.

2. The combination of claim 1 wherein the sides of the block whichconfront the pivot-supporting parts are curved to permit the lines ofcontact to move along said sides as the said parts are flexed.

3. The combination of claim 1 wherein the screw is swivelled in one ofthe parts between which it extends and is threaded into the other.

4. The combination of claim 1 wherein the screw is compound and hasthreads engaging the body and block respectively.

5. The combination of claim 1 wherein inward movement of the blockforces apart the pivot-supporting parts.

6. The combination of claim 1 wherein outward movement of the blockforces apart the pivot-supporting parts.

References Cited in the file of this patent UNITED STATES PATENTS2,910,900 Klein Nov. 3, 199

1. IN A TOOL OF THE MULTIPLE LEVER TYPE COMPRISING: (A) A PAIR OFINTERPIVOTED HEAD LEVERS HAVING WORKDEFORMING JAWS AT ONE SIDE OF THEPIVOT AND TAILS ON THE OPPOSITE, AND MEANS FOR MOVING THE TAILSCOMPRISING TWO ACTUATING LEVERS PIVOTED TOGETHER AT THEIR FORWARD ENDSAND, ADJACENT TO THEIR COMMON PIVOT, BEING PIVOTED RESPECTIVELY TO SAIDTAILS TO PROVIDE SHORT ARMS EXTENDING BETWEEN THE TAILS AS A TOGGLE, THEACTUATING LEVERS EXTENDING REARWARDLY FROM THE TAILS TO PROVIDEACTUATING ARMS TO WHICH FORCE MAY BE APPLIED TO OPERATE THE TOGGLE, (B)AND IN WHICH TOOL THE FORWARD END PORTION OF AT LEAST ONE OF THEACTUATING LEVERS IS A MASSIVE INTEGRAL BODY OF DUCTILE METAL IN WHICHBODY THE PIVOTS ARE ORGANIZED, THE BODY BEING CLEFT REARWARDLY IN APLANE EXTENDING BETWEEN SAID PIVOTS TO PROVIDE INTEGRALLY BASEDPROJECTING PIVOT-SUPPORTING PARTS ESSENTIALLY INFLEXIBLE AS AGAINSTSMALL STRAINS, (C) THE COMBINATION WITH SAID CLEFT BODY OF A BLOCKINTERPOSED BETWEEN THE PIVOT-SUPPORTING PARTS, SIDES OF THE BLOCK ANDSAID PARTS BEING SHAPED TO PROVIDE OUTWARD LATERAL PRESSURE ON THELATTER TO FLEX THE SAID PARTS AS THE BLOCK IS MOVED IN ONE DIRECTIONLENGTHWISE BETWEEN THEM AND A DEVICE COMPRISING A ROTATABLE SCREW ON THESPACE BETWEEN SAID PARTS AND EXTENDING BETWEEN SAID BLOCK AND THE BOTTOMOF THE CLEFT FOR ADJUSTABLY POSITIONING THE BLOCK.